1. Field of the Invention
The present invention relates generally to an animation creating apparatus and method for automatically creating a character animation representative of the expression of face or of actions of a person on an application of a personal computer or the like, as well as to a medium having an animation creating program recorded thereon. More particularly, it is directed to an animation creating apparatus and method acting as an authoring tool for automatically creating a character animation work by use of animation parts, as well as to a medium having an animation creating program recorded thereon.
2. Description of the Related Arts
Nowadays a lot of attention is being paid to authoring tools for creating multimedia title animation works using personal computers or workstations. In that process, an attempt to part the contents is made to ensure effective authoring. In the authoring tools for character animations, a series of meaningful actions or expressions are divided into animation parts, which are linked together, as needed, to create animation works.
FIG. 1 depicts a conventional animation creating apparatus which is generally indicated at 100. The animation creating apparatus 100 is constituted by an entry unit 102, an arithmetic unit 104, a file 106 and a display unit 108. The arithmetic unit 104 is provided with a file control unit 110 and an animation composite unit 112. This animation creating apparatus 100 is concretely provided as an application program and is installed in a personal computer or a workstation for use as an authoring tool for creating an animation work. The file 106 stores for example animation parts 114-1 to 114-7 which are obtained by parting a series of motions or expressions of face as shown in FIG. 2. The animation parts 114-1 to 114-7 are given part IDs 1 to 7, respectively, as part names. In the case of creating an animation work, a story is first determined and then the animation parts 114-1 to 114-7 required for the story are selected in consideration for the context or mutual relationship. Based on the thus selected parts, animation part names are described in an animation sequence 116 in sequence, e.g., in the order of xe2x80x9cID1, ID5, . . . ID3xe2x80x9d as shown. Finally, the animation parts are continuously reproduced in accordance with the animation sequence 116.
Incidentally, in order to create a high-quality animation work in conformity with the story, there is a need to take into consideration smooth variations in the expression or motions between the adjacent animation parts selected. In the prior art animation creating apparatus, however, the work for selecting and linking together animation parts in conformity with the story is a manual editing work, taking a lot of labor and time for the completion of the animation work. In other words, to obtain a high-quality animation presenting smooth variations in the expression or actions, there must be repeated a modifying work in which once created animation work is reedited while being reproduced, which results in laborious work for the completion. In particular, to create a high-quality animation, a plenty of animation parts must be prepared, so that increased number of the animation parts renders the editing work for the selection and linkage of animation parts more laborious.
According to the present invention there is provided an animation creating apparatus for simply editing an animation work ensuring a smooth variation in the expression and actions by use of animation parts of a character.
The animation creating apparatus of the present invention comprises a storage unit, an entry unit and an arithmetic unit. The storage unit stores animation parts indicative of a series of actions and expressions of a person divided into a plurality of frames and stores attribute values of the animation parts. The entry unit enters the animation part attribute values in accordance with proceeding of a story. The arithmetic unit selects animation parts from the storage unit using the animation part attribute values entered through the entry unit, and it links the thus selected animation parts together to create an animation in conformity with the story. In this manner, by storing as data base animation parts of a divided character as well as attribute values indicative of actions and expression of the animation parts, and by entering desired attribute values in each proceeding step of a story to select animation parts to be linked together, the actions and motions of the character are subjected smooth variations in accordance with the story entered by means of the attribute values whereby it is possible to simply edit an animation work having a higher quality by use of the animation parts.
The storage unit stores, as the animation part attribute values, attribute values consisting of a plurality of items such as the character ID, the expression of face, the state of mouth, the state of eyes and the direction of face. The storage unit stores repetitive animation parts which appear repetitively by the designated number of times, and non-repetitive animation parts which appear only once. The entry unit enters all attribute values consisting of a plurality of items in each proceeding step of the story. Instead, the entry unit may enter only attribute values which have changed from the preceding step in each proceeding step of the story so as to achieve an easy entry work. The storage unit stores attribute values of the foremost frame and the endmost frame, of the plurality of frames providing the animation parts. In this case, the arithmetic unit upon the selection of animation parts from the storage unit judges whether connectivity of animation parts is good or poor on the basis of attribute values in the current step and in the preceding step. The arithmetic unit, when poor connectivity is judged, changes the attribute value to reselect another animation part for better connectivity. More specifically, upon the selection of animation parts from the storage unit, the arithmetic unit compares an attribute value at the foremost frame in the current step with an attribute value at the endmost frame in the preceding step. The arithmetic unit, when non-coincidence is detected, judges the connectivity of animation parts to be defective and changes the attribute value at the endmost frame in the preceding step into the attribute value at the foremost frame in the current step to thereby reselect another animation part. In cases where the connectivity between two adjacent animation parts selected from the attribute values is poor with unsmooth variations in the actions and the expression, automatic selection of animation parts ensuring a smooth variation with better connectivity is carried out to remarkably reduce the work burden on the editing and enhance the quality of the animation work.
The storage unit stores, as impression data, coordinate values in a predetermined impression coordinate space, of a specific attribute value of the animation part. In this case, the entry unit enters, in place of attribute values, impression distance conditions such as a closest point or a farthest point in the impression coordinate space. When the impression distance conditions are entered in place of the attribute values, the arithmetic unit selects animation parts satisfying the thus entered impression distance conditions relative to animation parts selected in the preceding step. Herein, the impression coordinate space is a two-dimensional coordinate space having a coordinate axis along which the impression varies from strong to weak and having a coordinate axis along which the impression varies from warm to cold, with respect to the expression of face as the specific attribute values. The storage unit stores, as impression data, categories, which are impression regions defined in a predetermined impression coordinate space, of specific attribute values of the animation parts. In this case, the entry unit enters and designates, in place of an attribute value, a category in the impression coordinate space. The arithmetic unit selects an animation part belonging to the thus entered and designated category. Herein, if a plurality of animation parts lie within the thus entered and designated category, the arithmetic unit selects one of the plurality of animation parts at random. The storage unit further stores not only the impression data of the category to which the coordinate values belong in the impression coordinate space but also priorities of animation parts belonging to the same category. In such a case, the arithmetic unit, if a plurality of animation parts lie within the thus entered and designated category, selects one of the plurality of animation parts in accordance with the priorities. In this manner, by storing impression data as the attribute values of the animation parts and by entering the impression data as the attribute values, it is possible to designate the impression of an animation to be created such as warmness or sadness in the expression of face, to thereby assure that the total impression of the finished animation work results in the designated impression. Furthermore, use of the impression data simplifies the entry of the attribute values.
The present invention further provides an animation creating method for simply editing an animation work ensuring a smooth variation in the expression and actions by use of animation part of a character, the method comprising:
a storage step for storing animation parts indicative of a series of actions and expressions of a person divided into a plurality of frames and for storing attribute values of the animation parts;
an entry step for entering the animation part attribute values in accordance with proceeding of a story; and
an arithmetic step for selecting animation parts from the storage step using the animation part attribute values entered through the entry step, the arithmetic step linking the thus selected animation parts together to create an animation in conformity with the story.
The details of this animation creating method are substantially the same as those in the case of the apparatus configuration.
In addition, the present invention provides a computer readable record medium in which is stored an animation creating program for simply editing an animation work ensuring a smooth variation in the expression and actions by use of animation parts of a character. The animation creating program stored in the storage medium comprises a storage module for storing into a storage unit animation parts indicative of a series of actions and expressions of a person divided into a plurality of frames and for storing attribute values of the animation parts; an entry module for entering the animation part attribute values in accordance with proceeding of a story; and an arithmetic module for selecting animation parts from the storage module using the animation part attribute values entered through the entry module, the arithmetic module linking the thus selected animation parts together to create an animation in conformity with the story.
The above and other objects, aspects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.